Climate Change Issues Minister Paula Bennett says it's an ambitious target that won't be easy for New Zealand to achieve.

"All parts of society have a part to play in the transition to a lower emissions economy, from central and local government through to businesses, iwi and communities," she said.

The Paris Agreement was finalised in December with countries being called upon to sign and ratify the agreement from April of this year.

"The Paris Agreement is historic and changed the way the world thinks about climate change. Ratifying it early reinforces our commitment to this deal and our support for the global momentum to grow with lower emissions.

"It is clear that we need to be better prepared to adapt to these changes, so I am establishing a group of technical experts to look at things like the effects on infrastructure and economic growth."

Terms of reference and membership for the group will be released in the next few weeks.

The Government plans to finalise ratification by November to commit New Zealand's support by the UN's Framework Convention on Climate Change conference.